This application claims the benefit of U.S. application Ser. No. 60/969,070, filed Aug. 30, 2007, the contents of which are hereby incorporated by reference.
Priming piston reciprocating pumps have been well known for use in pumping highly viscous fluids such as sealants and adhesives. Such pumps have traditionally had a metal-to-metal clearance between the piston guide and the piston on the order of 0.020 inches. The large gap allowed the piston guide and piston seat to rock side to side and wear unevenly and prematurely with such wear increasing the gap which in turn led to even more wear.
It is therefore an object of this invention to provide a priming piston pump which decreases wear of the piston seal, extends the functional life of the piston seal and reduces wear in the piston guide
The piston guide is provided with a bearing member in the inner diameter of the upper end (in normal orientation) of the guide. The bearing is formed of 25% carbon-filled PTFE and may be fitted without tools into the aforementioned ID. Such a bearing allows a negligible clearance to be utilized between the bearing and the piston leading to the desired reduction in wear.
These and other objects and advantages of the invention will appear more fully from the following description made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.
A priming piston reciprocating pump 10 is shown in
It is contemplated that various changes and modifications may be made to the piston guide assembly without departing from the spirit and scope of the invention as defined by the following claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2008/074990 | 9/2/2008 | WO | 00 | 2/3/2010 |
Number | Date | Country | |
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60969070 | Aug 2007 | US |